Facebook has scaled their service to over a billion users, which is very impressive. At some point, however, PHP became their bottleneck. Turns out that rewriting over a million lines of code, even in another language, is not a viable option. So if you cannpt change the application, why not change the platform? That is exactly what Facebook did when they created HipHop. HipHop was great, but ultimately failed. Now, the new kid on the block is HHVM, an alternative runtime for PHP. Will HHVM replace PHP? Should you care? Sketching out the history of the project, and its potential future, we will look not only from a technical point of view, but also analyze the business impact.